Apparatus and method for recovery of a system for disc-shaped objects

ABSTRACT

An apparatus for recovery in the system for processing disc-shaped objects is disclosed. The system is provided with an OHT that places and/or removes at least one FOUP containing disc-shaped objects onto and/or off of a loadport. A light barrier arrangement is attached in front of a region of the loadport, which is designed for placing and/or removing a FOUP by means of the OHT. An input device is provided through which the OHT resumes the process of placing and/or removing the FOUP when this is stopped by an interruption of the light barrier arrangement.

RELATED APPLICATIONS

This application claims priority to German patent application number DE10 2004 062 594.8, filed Dec. 24, 2004, which is incorporated herein byreference in its entirety.

FIELD OF INVENTION

The invention relates to an apparatus for recovery in a system forprocessing disc-shaped objects. In particular, the invention relates toan apparatus for recovery in a system for processing disc-shaped objectswith an OHT provided to the system that places and/or removes at leastone FOUP with disc-shaped objects on and/or from a loadport.

Furthermore, the invention relates to a method for recovery in a systemfor processing disc-shaped objects.

BACKGROUND OF THE INVENTION

In semiconductor manufacturing, wafers or disc-shaped substrates,respectively, are sequentially processed in a multiplicity of processingsteps during the production process. The disc-shaped substrates aretransported to the systems in containers, the FOUPs. The variousprocessing steps are then carried out in the systems. The FOUPs aredelivered or transported by an OHT to the system's loadport.

US patent application 2003/0053892 A1 discloses how the individual FOUPsare transported to a loadport by means of an OHT. However, this patentapplication does not disclose a device that monitors whether objects orthe like are present in the transport path of the FOUP from the OHT tothe base plate of the loadport.

US patent application 2002/0155641 A1 discloses an apparatus forpositioning a loadport in a processing machine. The apparatus has a baseplate in which at least two vertical bore holes are implemented thatinteract with the corresponding pins in the processing machine. Apositioning block is provided for positioning in which at least onehorizontal borehole is provided. The position of the loadport isdetermined via the borehole by means of a light source and a detector.

SUMMARY OF THE INVENTION

The object underlying the invention is to create an apparatus thatenables quick and inexpensive continuation of operation in case of amalfunction in placing and/or removing a FOUP on and/or from a loadport.

This object is solved by an apparatus for recovery in a system forprocessing disc-shaped objects, whereby an OHT that places and/orremoves at least one FOUP containing disc-shaped objects on and/or offfrom a loadport is provided to the system; in that a light barrierarrangement is attached in front of an area of the loadport, which isimplemented for placing and/or removing a FOUP by means of the OHT, andin that an input device is provided by which the OHT can be reset whenthe placing and/or removing has been stopped by an interruption of thelight barrier arrangement.

A further object of the invention is to make available a method by whichquick and inexpensive continuation of operation with the apparatus ispossible when a malfunction in placing and/or removing a FOUP on and/orfrom a loadport occurs.

This object is solved by a method with the following characteristics:

interruption of the light barrier arrangement during placing or removinga FOUP on and/or from a loadport;

monitoring whether interruption of the light barrier arrangement isongoing; and

recovery and continuation of placing of the FOUP or removing of the FOUPon and/or from the loadport.

It is particularly advantageous when an OHT is provided with which atleast one FOUP with disc-shaped objects may be placed and/or removed onand/or from a loadport, for recovery in the system for processingdisc-shaped objects. The system is provided with a light barrierarrangement, whereby an input device is provided by means of which theinterruption of the process of placing and/or removing a FOUP by the OHTcan be reset when the interruption in placing and/or removing is causedby an interruption in the light barrier arrangement.

The light barrier arrangement comprises a linear arrangement of severalindividual light barriers, whereby each is comprised of a light sourceand a receiver. A first and a second side wall are attached above theloadport. The input opening for the system is implemented between thefirst and the second side wall. The light barrier arrangement isattached to an end of the first and the second wall that is facing awayfrom the system.

The input device is a visual display screen that is connected to acontrol unit for the system and the OHT. The visual display screen canbe implemented as a touchscreen. The system is connected to a signaltower that comprises several signal lights.

The method for recovery in the system for processing disc-shaped objectsis equally advantageous. Here, the interruption in the light barrierarrangement during placing or removing a FOUP on and/or from a loadtransport is first registered, and the loading/unloading processimmediately interrupted. Then monitoring begins to determine whether theinterruption of the light barrier arrangement is ongoing. Finally,recovery is undertaken and placing the FOUP or removing the FOUP onand/or from the loadport is resumed.

Further advantageous developments of the invention may be inferred fromthe subclaims.

The above and other features of the invention including various noveldetails of construction and combinations of parts, and other advantages,will now be more particularly described with reference to theaccompanying drawings and pointed out in the claims. It will beunderstood that the particular method and device embodying the inventionare shown by way of illustration and not as a limitation of theinvention. The principles and features of this invention may be employedin various and numerous embodiments without departing from the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, reference characters refer to the sameparts throughout the different views. The drawings are not necessarilyto scale; emphasis has instead been placed upon illustrating theprinciples of the invention. Of the drawings:

The subject of the invention is schematically represented in thediagram, and is described below based on the figures. They show:

FIG. 1 a schematic view of a system that processes disc-shapedsemiconductor substrates, whereby the disc-shaped semiconductorsubstrates are delivered in a FOUP via an OHT (overhead hoisttransportation) to a loadport of the system;

FIG. 2 a perspective view of a loadport connected to a system forprocessing disc-shaped substrates;

FIG. 3 a perspective view of a loadport connected with the light barrierarrangement according to the invention;

FIG. 4 a schematic representation of a block diagram of the methodaccording to the invention for placing a FOUP; and

FIG. 5 a schematic representation of a block diagram of the methodaccording to the invention for removing a FOUP.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic view of a system 100 that processes disc-shapedsemiconductor substrates. The disc-shaped semiconductor substrates aredelivered to a loadport 20 of the system 100 in a FOUP 101 via an OHT102 (overhead hoists transportation). The loadport 20 comprises a baseplate 21 onto which the FOUP 101 may be placed so that the disc-shapedsubstrates may be processed by the system 100. The system 100 is furtherprovided with a signal tower 105 that may comprise several light sources104 of varying color. The lights 104 give the operator an indication ofpotential errors. Furthermore, the system 100 is provided with a visualdisplay screen by means of which the operator may make inputs. Thevisual display screen makes available to the operator several inputfields 107 for the purpose. Thus, for example, the operator may initiateautomatic recovery via at least one of the input fields 107. Similarly,the operator may confirm a manual reset of the system 100 via the visualdisplay screen.

FIG. 2 is a perspective view of a loadport 20 that is connected to asystem 100 for processing disc-shaped substrates. The loadport 20 isconnected with the system 100 and forms an interface between the system100 for processing the disc-shaped substrates and that for inputtingdisc-shaped substrates in the system 100. The loadport 20 has a baseplate 21 onto which a FOUP 101 can be placed. The base plate 21 itselfbears a connection plate 22 that is implemented in accordance with theSEMI E15 standard and interlocks with a bottom side (not represented) ofthe FOUP 101. By interlocking, the FOUP 101 is securely seated on theloadport 20. In addition to the aforedescribed interlocking, couplingelements (not represented) between the FOUP 101 and a loadport 20 gripeach other to achieve a secure seat. A FOUP 101 filled with disc-shapedobjects can therefore not be accidentally knocked off of the loadport20, so that an additional level of security to protect the disc-shapedobjects is built in. In addition, several lights 23 are provided at theloadport 20, which indicate the correct positioning of the FOUP 101 onthe loadport 20. Similarly, the lights 23 indicate whether the FOUP 101has been placed on the loadport or whether the present FOUP may beremoved.

FIG. 3 is a perspective view of a loadport 20 with the operating element30 according to the invention. The operating element 30 makes itpossible for a FOUP 101 to be placed onto the loadport withoutinitializing the lock device, by means of which the FOUP 101 isprevented from being removed before the disc-shaped objects contained inthe FOUP 101 have been processed by the system 100. Once the operatorhas placed a FOUP 101 on the loadport and presses or activates theoperating element 30, the disc-shaped objects contained in the FOUP 101are processed. If the operator parks a FOUP 101 on the loadport 20without activating the operating element 30, the FOUP 101 is secured andfixed on the loadport 20 and can be removed and placed again as desired.A light barrier arrangement 24 is provided in a suitable manner at theloadport 20, with which events or objects that should not be present inthe load path of the FOUP 101 by means of the OHT 102 may be detected orregistered. An event may, for example, include the operator'sinterrupting the light barrier arrangement 24 with his elbow. The lightbarrier arrangement 24 is a linear arrangement of several individuallight barriers, whereby each comprises a light source and a receiver.For the spatial arrangement of the light barrier arrangement 24 a firstand a second wall 26 and 27 are attached above the loadport 20, andbetween which an input opening 28 for the system is provided. The lightbarrier or the light barrier arrangement 24 are each provided as alinear arrangement at the end of the first and the second wall 26 and 27that faces away from the system.

FIG. 4 is a schematic representation of a block diagram of the methodaccording to the invention for placing a FOUP 20. The E84 load sequence40 between the OHT 102 and the loadport 20 has begun. During the processof placing the FOUP 101 via the OHT 102 there is an interruption 41 ofthe light barrier, which interrupts the process of placing the FOUP 101.An alarm is given 43 on the visual display screen and/or signal tower.The interruption of the light barrier is eliminated 44 by the operator,if it is still ongoing. The system conducts a status inquiry 45 todetermine whether the interruption has been eliminated or not. If theresult of the status inquiry 45 is that the interruption has not beeneliminated, a service technician will have to be brought in. If theresult of the status inquiry 45 is that the interruption was eliminated,a further status inquiry 46 is made to determine whether the systemshould undertake an automatic recovery. If the result of the statusinquiry 46 is that no automatic recovery should be undertaken, therethen follows an action 471, by which the OHT is manually reset. Aconfirmation 472 that a manual reset has taken place appears on thevisual display screen. The alarm 473 of the light barrier is reset, andthe E84 load sequence is resumed 474.

If the result of the status inquiry 46 is that an automatic recoveryshould be undertaken, this is then done by the operator's selection 481of automatic recovery. After the selection 481, the light barrier isreset 482. Subsequently, an ES signal is given that permits resumption483 of the E84 load sequence. Finally, the E84 load sequence isconcluded 484. This means that placing of the FOUP 101 on the loadporthas been concluded.

FIG. 5 is a schematic representation of a block diagram of the methodaccording to the invention for removing a FOUP 101. The E84 on loadsequence 50 between the OHT 102 and the loadport 20 has begun. Duringthe process of removing of the FOUP 101 via the OHT 102 there is aninterruption 51 of the light barrier, and the process of removing theFOUP 101 is therefore interrupted. An ES signal is then given 52 so thatthe loadport 20 stops the OHT 102. An alarm is then registered 53 on thevisual display screen and/or a signal tower. The interruption of thelight barrier is eliminated 54 by the operator, if it still exists. Thesystem conducts a status inquiry 55 to determine whether theinterruption has been eliminated or not. If the result of the statusinquiry 45 is that the interruption has not been eliminated, a servicetechnician will have to be brought in. If the result of the statusinquiry 55 is that the interruption was eliminated, a further statusinquiry 56 is initiated to determine whether the system should undertakean automatic recovery. If the result of the status inquiry 56 is that noautomatic recovery should be undertaken, there then follows an action571, by which the OHT is manually reset. A confirmation 572 that amanual reset has taken place appears on the visual display screen. Thealarm 573 of the light barrier is reset, and the E84 unload sequence isresumed 574.

If the result of the status inquiry 56 is that an automatic recoveryshould be undertaken, this is then done by the operator's selecting 581automatic recovery. After the selection 581, the light barrier is reset582. Subsequently, an ES signal is given that permits resumption 583 ofthe E84 unload sequence. Finally, the E84 unload sequence is concluded584. This means that removing the FOUP 101 from the loadport has beencompleted.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. Apparatus for recovery in a system for processing disc-shapedobjects, whereby an OHT is provided for the system, which places and/orremoves a FOUP with disc-shaped objects on and/or from a loadport,wherein a light barrier arrangement is attached in front of a region ofthe loadport that is implemented for placing and/or removing a FOUP bythe OHT, and wherein an input device is provided by which the OHT can bereset when the placing and/or removing is stopped by interruption of thelight barrier arrangement.
 2. Apparatus according to claim 1, whereinthe light barrier arrangement comprises a linear arrangement of severalindividual light barriers, whereby each comprises a light source and areceiver.
 3. Apparatus according to claim 2, wherein a first and asecond wall are attached above the loadport, between which the inputopening for the system is implemented, and wherein the lineararrangement of a light barrier is provided at the end of the first andthe second wall that faces away from the system.
 4. Apparatus accordingto claim 1, wherein the input device is a visual display screen that isconnected to the system and the OHT by a control mechanism.
 5. Apparatusaccording to claim 4, wherein the visual display screen is atouchscreen.
 6. Apparatus according to claim 1, wherein the system isconnected with a signal tower that comprises several lights. 7.Apparatus according to claim 1, wherein the disc-shaped object is awafer, or a wafer on a glass substrate, or a mask for lithography, or aflat-panel display.
 8. Method for recovery in a system for processingdisc-shaped objects, characterized by the following steps: interruptionof the light barrier arrangement during placing or removing a FOUP onand/or from a loadport; monitoring whether interruption of the lightbarrier arrangement is ongoing; and recovery and continuation of placingof the FOUP or removing of the FOUP on and/or from the loadport. 9.Method according to claim 8, wherein automatic recovery is selected bythe operator from the visual display screen.
 10. Method according toclaim 9, wherein the alarm caused by the light barrier is reset as aresult of automatic recovery; wherein an ES signal is given to resumethe process; and wherein the E84 load/unload sequence is concluded. 11.Method according to claim 8, wherein manual recovery is selected by theoperator, whereby the OHT is manually reset and a manual reset isconfirmed on the visual display screen.
 12. Method according to claim11, wherein the alarm caused by the light barrier is reset, and whereinthe E84 load/unload sequence is restarted.
 13. Method according to claim8, wherein a service technician must be called if the interruption ofthe light barrier arrangement cannot be eliminated.
 14. Method accordingto claim 8, wherein the disc-shaped object is a wafer, or a wafer on aglass substrate, or a mask for lithography, or a flat-panel display.